0:00:22 > 0:00:25APPLAUSE AND CHEERING
0:00:29 > 0:00:31Well, hello!
0:00:31 > 0:00:35Hello, hello, hello, hello, hello, hello, hello, hello!
0:00:35 > 0:00:38And welcome to QI,
0:00:38 > 0:00:40where we bring you a television first -
0:00:40 > 0:00:43a quiz show with no answers.
0:00:43 > 0:00:46Tonight we depart from the certainties of everyday life
0:00:46 > 0:00:50to explore the realm of hypothetical questions.
0:00:50 > 0:00:51Or do we?
0:00:51 > 0:00:54It's a job for only the very finest minds,
0:00:54 > 0:00:57by which I mean the potential Johnny Vegas!
0:01:00 > 0:01:03The possible Sandi Toksvig!
0:01:06 > 0:01:10And the increasingly unlikely Alan Davies.
0:01:13 > 0:01:14Now...
0:01:14 > 0:01:19tonight is the 99th recording of QI
0:01:19 > 0:01:23and to celebrate, we have with us the man who thought it all up in the first place.
0:01:23 > 0:01:27He can dish it out, but let's see if he can take it, Mr John Lloyd!
0:01:32 > 0:01:36They all have appropriately quizzical buzzers.
0:01:36 > 0:01:37Sandi goes...
0:01:37 > 0:01:40SANDI: "Um..."
0:01:40 > 0:01:41Johnny goes...
0:01:41 > 0:01:43- JOHNNY:- "Hmm..."
0:01:43 > 0:01:44John goes...
0:01:44 > 0:01:47- JOHN:- "Ooh, um..."
0:01:47 > 0:01:49- And Alan goes... - Sir, Sir! I know! Me, sir!
0:01:50 > 0:01:52As if!
0:01:52 > 0:01:56And let's open our minds now to the possibilities of question one.
0:01:56 > 0:02:02What's the best way to weigh your own head?
0:02:02 > 0:02:05LAUGHTER
0:02:05 > 0:02:06Any thoughts?
0:02:06 > 0:02:10Well, cut it off would obviously be the most accurate way.
0:02:10 > 0:02:13Then someone else could weigh it, but you couldn't!
0:02:16 > 0:02:19That would be the problem. The question was...
0:02:19 > 0:02:23You introduced us and you normally introduce me last. It caught me out.
0:02:23 > 0:02:25I was applauding myself!
0:02:25 > 0:02:26Oh, bless!
0:02:26 > 0:02:28Alan Davies!
0:02:29 > 0:02:32And I was applauding myself insincerely.
0:02:33 > 0:02:37That's what Soviet leaders do! Or chimpanzees.
0:02:37 > 0:02:39- One or the other.- Yeah.
0:02:39 > 0:02:42Why would you want to weigh your own head?
0:02:42 > 0:02:46It's a boys' thing. Imagine some poor woman married to a scientist.
0:02:46 > 0:02:49She's at home, wormed the dog, fed the children, all sorted,
0:02:49 > 0:02:54and her husband says, "Good news, dear. I've weighed my own head."
0:02:54 > 0:02:57It may not seem like the most useful thing to do,
0:02:57 > 0:02:59but it does employ interesting scientific ideas
0:02:59 > 0:03:02on which we all depend.
0:03:02 > 0:03:05Is it that thing that David Frost used to tell that joke for years?
0:03:05 > 0:03:10"Do you want to lose 12lbs of unsightly fat?
0:03:10 > 0:03:12"Cut off your head."
0:03:12 > 0:03:15- Was that his joke?- He used to tell that a lot.
0:03:15 > 0:03:19What is one of the most famous ancient moments of scientific discovery?
0:03:19 > 0:03:22- SANDI: It's the bath. - Is it Archimedes?
0:03:22 > 0:03:25Archimedes and the bath. What did Archimedes do and why...
0:03:25 > 0:03:28Displaced. You could put your head in a bucket.
0:03:28 > 0:03:30- Is that right?- I've no idea.
0:03:30 > 0:03:34- Join in.- I was going to weigh myself, go to the swimming baths,
0:03:34 > 0:03:38and bob and then get people to feed me until I sank.
0:03:40 > 0:03:43Then come back out and weigh myself again.
0:03:43 > 0:03:46Yep. That sounds much more scientific!
0:03:48 > 0:03:50So by displacement of the water, you can tell...
0:03:50 > 0:03:54Take a big bucket and fill it with water, and drop your head in.
0:03:54 > 0:03:59Because water and the density of your head are about the same, you get a close approximation
0:03:59 > 0:04:02by the amount of water that you displace.
0:04:02 > 0:04:05- You can put apples in to make it fun.- Bob for apples, yes.
0:04:05 > 0:04:08And what did your head weigh when you tried this?
0:04:08 > 0:04:15What would you say is the average weight? The University of Sydney weighs heads quite a lot.
0:04:15 > 0:04:18- They have a pretty good average. - By dunking them in buckets?
0:04:18 > 0:04:24- They don't actually dunk them. - Is it 12lbs?- It's 4.5 to 5 kilos,
0:04:24 > 0:04:26- which is... - I've no idea.
0:04:26 > 0:04:272.2 kilos in a pound.
0:04:27 > 0:04:29Not far off.
0:04:29 > 0:04:32- 2.2.- It's about 12lbs. - Yes, about 12 lbs. Well done.
0:04:32 > 0:04:34I'll give you a point for 12lbs, John.
0:04:34 > 0:04:37You may have negotiated us a point!
0:04:37 > 0:04:42Surely you should give those points to David Frost who thought of 12lbs in the first place.
0:04:42 > 0:04:46- He hadn't cut his head off, though. - What if you get an air pocket in your ears?
0:04:46 > 0:04:48- A pocket?- You know, air pockets.
0:04:48 > 0:04:51But the air cavities are cancelled out by...
0:04:51 > 0:04:54Fingers out - you won't hear the answer.
0:04:54 > 0:04:56APPLAUSE
0:04:58 > 0:05:03You have bones that are denser than water and air pockets that are lighter.
0:05:03 > 0:05:07Together, it does seem that the head averages about water.
0:05:07 > 0:05:10So it's a good displacement test.
0:05:10 > 0:05:15But there is a modern piece of technology that can do it to frightening degrees of accuracy.
0:05:15 > 0:05:18- A laser or something. - No, a CAT scan, a CT.
0:05:18 > 0:05:23They can tell the density of every little tiniest part of the brain
0:05:23 > 0:05:26and skull and all the rest of it and tot it up.
0:05:26 > 0:05:29My dad's got heavy eyes.
0:05:29 > 0:05:33- Has he, now?- Yeah.- Have you weighed his eyes?- No, we've not,
0:05:33 > 0:05:36but he's very fearful of leaning forwards.
0:05:36 > 0:05:37Is he?
0:05:37 > 0:05:41- Honestly!- Do they crash through his glasses?- He won't lean forwards.
0:05:41 > 0:05:47- He thinks they'll come out! - Are they on springs like those things you buy?
0:05:47 > 0:05:49We got rid of novelty dad.
0:05:50 > 0:05:53This is mental dad!
0:05:53 > 0:05:57My grandfather had two glass eyes, and yet he could see.
0:05:57 > 0:06:02What happened was, he sadly lost one eye. He wasn't careless, he was ill.
0:06:02 > 0:06:08And he had a glass eye made, exactly like his other perfectly working blue Scandinavian eye.
0:06:08 > 0:06:11Then he had one made that was bloodshot.
0:06:11 > 0:06:14It was known as Grandpa's party eye.
0:06:14 > 0:06:16He kept it in a box on the mantelpiece.
0:06:16 > 0:06:21When he went out for the evening, he'd take out the blue one and put in the bloodshot one.
0:06:21 > 0:06:25He'd say, "I'm going out now and I shan't be back till they match!"
0:06:25 > 0:06:27Oh, that's brilliant!
0:06:27 > 0:06:29Brilliant!
0:06:30 > 0:06:32Fantastic.
0:06:32 > 0:06:35- I assume...- I thought he had two glass eyes like that!
0:06:35 > 0:06:38- That would be silly!- Did he have a hole at the back?
0:06:38 > 0:06:41Was your granddad Nookie Bear?
0:06:41 > 0:06:46Talking of heads, do you know anything about Sir Francis Drake? I don't mean Sir Francis Drake.
0:06:46 > 0:06:50But as I've mentioned him, do you know anything about him?
0:06:50 > 0:06:52LAUGHTER AND APPLAUSE
0:06:54 > 0:06:57- Something to do with bowling. - That's right.
0:06:57 > 0:06:59He was in the navy!
0:07:00 > 0:07:03Let's move on from Francis Drake. Thanks.
0:07:03 > 0:07:06What do you know about Sir Walter Raleigh?
0:07:07 > 0:07:10He invented the bicycle.
0:07:10 > 0:07:16- His wife carried his head around in a bag for more than 30 years. - Excellent.- A velvet bag.
0:07:16 > 0:07:18A red velvet bag, yes.
0:07:18 > 0:07:24- Sir Walter was executed.- I see why John had to invent this show for this kind of information!
0:07:24 > 0:07:27You carried it around much as Lady Raleigh carried the head.
0:07:27 > 0:07:30- It was on Buzzcocks last week. - Was it?
0:07:32 > 0:07:38- What sort of bag? Was it a sealed bag, a cool box?- I don't know.
0:07:38 > 0:07:39People did keep heads.
0:07:39 > 0:07:44I bet it was a few years before anybody wanted to sit next to her at dinner!
0:07:44 > 0:07:48- Lady Raleigh?- Do you not think? "Oh, she's not going to bring the head, is she?"
0:07:51 > 0:07:55Very fine. Don't know how we got there, but like many of the questions in tonight's show
0:07:55 > 0:08:00there's no one correct answer, but dunking your head in a bucket is a good start.
0:08:00 > 0:08:05If that has you scratching your head, when might you engage in paradoxical undressing?
0:08:05 > 0:08:11- So you're undressing but you're actually dressing?- No, it's not really paradoxical.
0:08:11 > 0:08:15- Is it physics or mathematics?- No. - It's counter-intuitive undressing. - Yes.
0:08:15 > 0:08:19So taking your clothes off if Jeremy Clarkson asks you would be...
0:08:22 > 0:08:24- Miaow!- ..would be silly.
0:08:24 > 0:08:29It's taking your clothes off when taking your clothes off seems the worst idea you could have.
0:08:29 > 0:08:34- Is it some effect of hypothermia? Some mental...- Exactly what it is. - ..thing it does to you.
0:08:34 > 0:08:40- It may be mental, it may be physical. It's not understood. - Oh, that is very unpleasant!
0:08:41 > 0:08:44Let's go back to the previous picture!
0:08:44 > 0:08:48It's one of the peculiar side-effects of hypothermia.
0:08:48 > 0:08:54When you're actually dying of cold, almost the last thing you do, very commonly, not always,
0:08:54 > 0:08:56is take all your clothes off.
0:08:56 > 0:08:59People think it may be a delusional thing.
0:08:59 > 0:09:04But also your blood vessels near your skin tend to just give up and open,
0:09:04 > 0:09:10and maybe people feel very hot. Because you never survive past that stage, you can't ask someone
0:09:10 > 0:09:14why they did it. But it is a common thing for people to do and they're freezing.
0:09:14 > 0:09:22I went in freezing water once. I screamed and swam about and I went shocking, livid pink and felt hot.
0:09:22 > 0:09:25I was perhaps seconds from death!
0:09:25 > 0:09:26Maybe you were!
0:09:26 > 0:09:30- Maybe you're one of the few who survived it!- Yeah.
0:09:30 > 0:09:36What sort of temperature do you think would start you on the road to hypothermia? Body temperature,
0:09:36 > 0:09:38not outside temperature.
0:09:38 > 0:09:40What's the temperature in here?
0:09:41 > 0:09:43I'd say pretty quickly.
0:09:43 > 0:09:47Don't think it would have to drop much. Four or five degrees below normal?
0:09:47 > 0:09:52That's right. 35 degrees Celsius. Once your temperature gets below that.
0:09:52 > 0:09:57Interestingly, in the coldest cities in the world, hypothermia is very rare.
0:09:57 > 0:10:01Much more common in Britain where it doesn't get very cold.
0:10:01 > 0:10:06There's a very remarkable Briton called Lewis Pugh. Have you heard of Lewis Pugh?
0:10:06 > 0:10:10He's a man who's able to control his own body temperature.
0:10:10 > 0:10:15He does endurance cold swimming. He's the only person known to science who can do what he can do.
0:10:15 > 0:10:17He can swim in cold conditions
0:10:17 > 0:10:19unlike anybody else.
0:10:19 > 0:10:23He's able to raise his body temperature at will.
0:10:23 > 0:10:25It's completely startling.
0:10:25 > 0:10:29- A superhero!- He can stop himself shivering. He's an incredible figure.
0:10:29 > 0:10:33We contacted him. He said that he thought he could do this...
0:10:33 > 0:10:36He said he's not coming in here cos it's freezing!
0:10:36 > 0:10:41He thought he could do this because he had trained himself over years and years
0:10:41 > 0:10:45to do these endurance swims in incredibly cold waters.
0:10:45 > 0:10:49His body saw it coming and prepared for it. That was his explanation.
0:10:49 > 0:10:52Cold water has a bad effect on a boy. He looks good there,
0:10:52 > 0:10:55but I bet he doesn't fill his swimming trunks when he gets out!
0:10:55 > 0:10:58Actually, this is not that unusual.
0:10:58 > 0:11:01We went on this yoga thing recently.
0:11:01 > 0:11:07The yoga teacher was saying that these sadhus in India
0:11:07 > 0:11:09can do this body raising thing.
0:11:09 > 0:11:12They did some scientific experiments in the States
0:11:12 > 0:11:17where they shipped in these guys, wiry guys with turbans on,
0:11:17 > 0:11:21and they put wet towels on them. The turn up their own body temperature
0:11:21 > 0:11:24and literally steam the towels dry, in a few minutes.
0:11:24 > 0:11:28- Extraordinary. - SANDI: Can you hire these people?
0:11:28 > 0:11:32It's a good act if they can get on Britain's Got Talent!
0:11:32 > 0:11:36That would be good. "What are you going to do?" "I'm going to dry this wet towel!"
0:11:41 > 0:11:45You could do patterns on wet towels with your hands. "It's art!"
0:11:46 > 0:11:51Paradoxically, the last thing people do when freezing to death is take their clothes off.
0:11:51 > 0:11:55Now it's time for a round of quick-fire hypotheticals!
0:12:00 > 0:12:05So... All you have to do is tell me the first thing that comes into your head,
0:12:05 > 0:12:08quick-fire hypothetical questions.
0:12:08 > 0:12:10Let's say you found a fallen tree in the forest.
0:12:10 > 0:12:14Obviously it fell down before you arrived.
0:12:14 > 0:12:19- But did it make a sound as it fell? - Ooh, um...- No.
0:12:23 > 0:12:25No-one's going to say yes, are they?
0:12:25 > 0:12:27Yes, you're right.
0:12:27 > 0:12:32- Do you know where the question comes from?- It's a famous... - Bishop Berkeley.- Yes.
0:12:32 > 0:12:34A philosophical question.
0:12:34 > 0:12:37If there's no-one to hear a sound, is there a sound?
0:12:37 > 0:12:39It depends what you mean by sound.
0:12:39 > 0:12:43There isn't because sound is the vibration of the ear drum.
0:12:43 > 0:12:47- Y... Is it?- If there's no-one to hear it.- It depends, though.
0:12:47 > 0:12:51Part of the definition of sound is there has to be a recipient.
0:12:51 > 0:12:55Something makes the noise, the transmission of it, and reception of it.
0:12:55 > 0:13:00- If there's no reception of the noise, maybe it doesn't exist. - Other things are vibrating.
0:13:00 > 0:13:04But whether that vibration counts as a sound or not is a moot point.
0:13:04 > 0:13:08- Is the forest ever empty? - There isn't any sound if there's no-one to hear it.
0:13:08 > 0:13:13- It's a mooty point.- There's the speed of sound and if it's only what happens in the ear,
0:13:13 > 0:13:16how do you get that speed between that and your ear?
0:13:17 > 0:13:19LAUGHTER
0:13:19 > 0:13:21No, I'm...
0:13:21 > 0:13:23APPLAUSE
0:13:23 > 0:13:28Maybe by the time that tree's fallen and you get there, that sound is half way round the world.
0:13:28 > 0:13:31And making someone else very nervous.
0:13:31 > 0:13:32"Aghh!"
0:13:32 > 0:13:35- Stephen, are you sure about this? - Well,
0:13:35 > 0:13:39no-one is sure. That's the point. That's why it's hypothetical.
0:13:39 > 0:13:42To a semanticist or a neurologist, they may say sound is that.
0:13:42 > 0:13:46A physicist would say the propagation of sound waves is sound.
0:13:46 > 0:13:49Whether or not there is an ear to vibrate, it is a sound wave.
0:13:49 > 0:13:53- If it's a sound wave...- I disagree that they are sound waves, because...
0:13:53 > 0:13:55You may disagree. You're welcome to!
0:13:55 > 0:14:01A vibration can only become a sound wave when there's an ear to receive it.
0:14:01 > 0:14:05It's rather like - do you remember we talked... A thing that astonished me.
0:14:05 > 0:14:08Did you know that light is invisible?
0:14:08 > 0:14:13In a dark vacuum, if you shoot a beam of light across the eyeballs,
0:14:13 > 0:14:17- you can't see it because you can only see...- But what about sound? - ..what light hits.
0:14:17 > 0:14:21It's the same thing. People say but that's a stupid answer
0:14:21 > 0:14:26because the definition of light is something that goes into your eye and is then received.
0:14:26 > 0:14:28Until it does that, it's not light.
0:14:28 > 0:14:31But we have all kinds of things like not ears, for example.
0:14:31 > 0:14:37Are you saying it's not sound if it registers on a recording device that is left there?
0:14:37 > 0:14:40It bends the needle of a recording device. Does the machine not hear?
0:14:40 > 0:14:44Is it not a sound wave that is causing the machine to register?
0:14:44 > 0:14:49- Yes, but Bishop Berkeley... - I'm talking about you, not Bishop Berkeley!
0:14:49 > 0:14:53The point is, it's not as simple to just say yes or no.
0:14:53 > 0:14:56Go on, Stephen! Go on! Go on!
0:14:56 > 0:14:58You've got him!
0:15:00 > 0:15:06It's a good question. We would have forfeited somebody who said yes as much as somebody who said no.
0:15:06 > 0:15:10- I thought you said there was no right answer.- Yes, that's why it's a good question.
0:15:10 > 0:15:17- There is no right answer. So your yes and your no...- Whatever I'd said would have been...- I'm afraid so.
0:15:17 > 0:15:21What if the tree fell and there was no-one there to see it, it should still be upright.
0:15:22 > 0:15:27- Very true.- It's like the illusion... - You're right.
0:15:27 > 0:15:31Anyway, Alan, are you keeping well?
0:15:31 > 0:15:34Until that tree fell over - there was a hell of a bang!
0:15:34 > 0:15:39It's a quick-fire hypothetical, don't forget, so we move on. OK.
0:15:39 > 0:15:43- You're talking to an England... - I can't do quick-fire! - Yes, you can, darling.
0:15:43 > 0:15:48If a quick-fire hypothetical round takes a really long time, is it still quick-fire?
0:15:48 > 0:15:51Good point! We'll find out!
0:15:52 > 0:15:56Very good point. You're talking to an alien in a distant galaxy
0:15:56 > 0:16:02- by radio. How could you explain which is right and which is left? - Breaker breaker.
0:16:02 > 0:16:06That would do it, would it? Just by saying "Breaker breaker", he would know...
0:16:06 > 0:16:11Well, it depends what height mast he had, but yeah, it should...
0:16:12 > 0:16:20- It's nice...- There's got to be alien truckers!- Fair point.
0:16:20 > 0:16:24- They must run freight.- I'll tell him what's left and right and if he's got a smokey on his arse.
0:16:24 > 0:16:29- Right. Right.- Hypothetically, are we looking at any common reference point?
0:16:29 > 0:16:34- That is the point. You can't... - "Can you see Mars. Yeah? We're on the right."
0:16:36 > 0:16:39"Can you see the spot on Jupiter?"
0:16:39 > 0:16:41You'd need something to reference.
0:16:41 > 0:16:44Yes. Semantically, there is no explanation for left or right
0:16:44 > 0:16:48without reference to a physical world that someone can identify.
0:16:48 > 0:16:51You can't explain it just by language. That's the point.
0:16:51 > 0:16:55Well, if they visited in a ship, you could give them a temporary tattoo.
0:16:55 > 0:17:01Yes, you could do that. Which is why we framed the question so specifically, saying...
0:17:01 > 0:17:04- Oh, talking on a radio. - ..tattoos were out.
0:17:04 > 0:17:07Ah, sorry. I'm just a problem solver by nature!
0:17:07 > 0:17:14- No, it's good.- Anyway, they may not have... We always draw them in that shape, two eyes.
0:17:14 > 0:17:18What if they've got four eyes and eight arms and don't have one or two...
0:17:18 > 0:17:20They may not be symmetrical in any way.
0:17:20 > 0:17:25- They might have other dimensions in all sorts.- They might have 19 versions of left.
0:17:25 > 0:17:27Imagine that on a Sat Nav!
0:17:27 > 0:17:31- Left-ish!- Not that one, not that one - that one!
0:17:31 > 0:17:34- L-l-l-l-l-left!- Why do we always...
0:17:34 > 0:17:37- Why do we always draw them like that?- I've no idea.
0:17:37 > 0:17:40They might have one eye in the middle.
0:17:40 > 0:17:42The ones that probed me looked nothing like that!
0:17:42 > 0:17:47Do you have a little thing in your head as a mnemonic when you forget left and right?
0:17:47 > 0:17:50- Do you do that?- I walk into traffic.
0:17:51 > 0:17:53Sorts it out straightaway!
0:17:55 > 0:17:57- Do you have a problem?- No, I don't,
0:17:57 > 0:18:03but if I have to think, I remember the thumb I used to suck as a very small child.
0:18:03 > 0:18:07- That's my right hand. No-one else have this?- This is like a therapy session!
0:18:07 > 0:18:11There's a wonderful story about a famous ocean liner captain.
0:18:11 > 0:18:14He had a silver box that he kept in his pocket.
0:18:14 > 0:18:18Every time before they came into port, he'd open the box, look, then put it away.
0:18:18 > 0:18:24After many years service, he finally died and his second in command said, "I must look at this box."
0:18:24 > 0:18:28He opened the box and it said, "Port - left, starboard - right."
0:18:29 > 0:18:31Brilliant.
0:18:31 > 0:18:35That's the point, though, you can't really find out.
0:18:35 > 0:18:39Now, a lorry-load of birds are being weighed on a weighbridge.
0:18:39 > 0:18:44At some moment, all the birds simultaneously rise off their perches and flap in the air.
0:18:44 > 0:18:48- So they're all alive. - Yeah. Does the lorry weigh less...
0:18:48 > 0:18:51- Yes.- ..when they rise up in the air? - Yes.- No.
0:18:51 > 0:18:55- Got a yes and no.- So they're not in contact with the actual...
0:18:55 > 0:18:57So it would weigh less.
0:18:57 > 0:19:02- Is it sealed, the lorry? - It's closed, it's got a tailgate. It's locked up.
0:19:02 > 0:19:06- They're inside the lorry.- Wouldn't there be pressure from the air?
0:19:06 > 0:19:09- Yes.- It's not... They don't. It weighs the same.
0:19:09 > 0:19:13It's something to do with, something very similar to, if you weigh yourself
0:19:13 > 0:19:16then go and do a number two and weigh yourself again,
0:19:16 > 0:19:19- you don't lose the weight of the number two.- Ah.
0:19:19 > 0:19:20LAUGHTER
0:19:20 > 0:19:23There we're in a slightly different territory!
0:19:23 > 0:19:26If you will do it on the scales!
0:19:32 > 0:19:36You're right. The answer is not to poo on the scales!
0:19:36 > 0:19:41- No...- Leave the scales, do the number two and come back to the scales!
0:19:41 > 0:19:45- You don't lose it when you... - The money I've wasted on enemas!
0:19:45 > 0:19:49I've argued this. It weighs the same and I can't remember the reason why!
0:19:49 > 0:19:54- I know this.- So they all lift off at the same time.
0:19:54 > 0:19:58It is weight. It's a bird/lorry system.
0:19:58 > 0:20:02- I know it's weird.- Is it sealed? Is it to do with it being sealed?
0:20:02 > 0:20:05If you're carrying a bowling ball and you're on the scales,
0:20:05 > 0:20:11- then you throw the ball in the air, it'll kill you.- You're part of something when you're inside it.
0:20:11 > 0:20:15- Because it's sealed...- The air's moving.- ..you and the Earth have created that weight.
0:20:15 > 0:20:19So wherever the birds are within that, it weighs the same.
0:20:19 > 0:20:23- Interestingly - you're absolutely right...- Don't pass it off that easily!
0:20:23 > 0:20:26The interesting question is if it's an open-top lorry
0:20:26 > 0:20:30and they jump up like that and jump up slightly higher,
0:20:30 > 0:20:34then they're out of the system, no longer part of the lorry/bird system.
0:20:34 > 0:20:36Then it would be lighter.
0:20:36 > 0:20:41Well done, everybody. It's time to move on from our hypotheticals.
0:20:41 > 0:20:43That was very quick!
0:20:43 > 0:20:47So, hypothetical problems are the curse of the practical man.
0:20:47 > 0:20:53Hypothetically, what would happen if Schrodinger put a Siamese cat in the fridge?
0:20:53 > 0:20:55In the fridge?
0:20:55 > 0:20:59- He wouldn't know if it was alive or dead.- Good.
0:20:59 > 0:21:01You're referring to Schrodinger's Cat, which is?
0:21:01 > 0:21:04- I learned about this on Horizon. - Very good.
0:21:04 > 0:21:08You don't know until you open the door whether the cat is alive or dead.
0:21:08 > 0:21:11That is the quantum paradox of Schrodinger's Cat.
0:21:11 > 0:21:14You're putting a Siamese cat in the fridge?
0:21:14 > 0:21:16What is the question?
0:21:16 > 0:21:19What would happen to the cat?
0:21:19 > 0:21:23It would get cold. What would happen to the fridge? Less milk left, probably!
0:21:23 > 0:21:25It would eat all the tuna melts!
0:21:25 > 0:21:27The tuna melts would go, yes.
0:21:27 > 0:21:32- But something quite extraordinary would happen.- It would turn into an ordinary cat.
0:21:32 > 0:21:36- Well, almost! Almost! - It would turn into a dog.
0:21:36 > 0:21:38- It's not that remarkable. - In seconds.
0:21:38 > 0:21:41"Miaow!" "Woof!"
0:21:42 > 0:21:46Let's have a look at a Siamese cat and see what's particular about it.
0:21:46 > 0:21:48White body, black face.
0:21:48 > 0:21:50You'd get a black body and a white face!
0:21:50 > 0:21:55It's got a white body and a black tail and black ears and black mouth and black socks.
0:21:55 > 0:21:58In other words, black extremities.
0:21:58 > 0:22:02- What is particular about the extremities of any mammal? - They're cold.
0:22:02 > 0:22:05- So if you put the whole animal in a fridge...- It goes black!
0:22:05 > 0:22:10- It goes black, Johnny. You're absolutely right.- That's death.
0:22:10 > 0:22:12That's what happens.
0:22:12 > 0:22:18Its fur has this peculiar colorant that keeps it pale in warm blood heat.
0:22:18 > 0:22:21But a small difference in temperature down,
0:22:21 > 0:22:25and it will lose the white or gain the black, whichever way you look at it.
0:22:25 > 0:22:29- When you take it out, does it go pale again?- Yes, back to normal.
0:22:29 > 0:22:32It would be worth trying, just for the laugh.
0:22:32 > 0:22:34I don't like cats very much.
0:22:34 > 0:22:38I'm sorry. So many cats, so few recipes! I just think...
0:22:38 > 0:22:39LAUGHTER
0:22:39 > 0:22:42I just think it sounds like fun.
0:22:42 > 0:22:47You can also try it on a Himalayan rabbit. They have the same issue.
0:22:47 > 0:22:50- Please don't try this at home!- No.
0:22:50 > 0:22:53Do you know about buttered cat?
0:22:53 > 0:22:56There's a recipe straightaway!
0:22:56 > 0:22:58- Buttered cat syndrome.- Delicious!
0:22:58 > 0:23:02You put butter on their paws to stop them going home if you've moved.
0:23:02 > 0:23:07This is a paradox. There are two laws. If you have buttered toast and drop it, what happens?
0:23:07 > 0:23:11- It falls butter side up.- Butter side down. If you drop a cat, what happens?
0:23:11 > 0:23:13- It falls butter side up.- No.
0:23:13 > 0:23:15- It falls...- It lands on its feet.
0:23:15 > 0:23:19So if you were to put some toast with the butter side up and attach it to a cat,
0:23:19 > 0:23:24what would happen is the cat would drop and it would have to revolve forever!
0:23:27 > 0:23:32- Because...- Then you've got an act! - ..the two laws would compete and it would be in balance!
0:23:32 > 0:23:34Would it work with margarine?
0:23:34 > 0:23:38I don't know. I think the law doesn't state that the margarine falls downwards.
0:23:38 > 0:23:42I can't believe it's not butter!
0:23:42 > 0:23:44What if it...
0:23:46 > 0:23:50What if it was margarine but the cat believed it was butter?
0:23:50 > 0:23:52Ah, the placebo effect! Exactly.
0:23:52 > 0:23:56Brilliant! Brilliant! You've all got the point.
0:23:56 > 0:24:01- What if cats discovered this and started to migrate? - Where would they go?
0:24:03 > 0:24:08I don't know! It's just a cat with a piece of toast! I'm not going to dictate where...
0:24:09 > 0:24:12Let's just keep it from them. So, yes,
0:24:12 > 0:24:15if you put a Siamese cat in the fridge for long enough,
0:24:15 > 0:24:19and it would have to be quite a long time, probably weeks, it would go black.
0:24:19 > 0:24:21And you mustn't!
0:24:21 > 0:24:25But after that voyage through a land where there are no wrong answers,
0:24:25 > 0:24:27we come to one where there is rarely a right one.
0:24:27 > 0:24:31To the realm of general ignorance. Fingers on buzzers
0:24:31 > 0:24:35and stop me when you know what I'm talking about.
0:24:35 > 0:24:39It's an insectivorous mammal, it's found all round the world.
0:24:39 > 0:24:41It's active at night,
0:24:41 > 0:24:43it's almost totally blind.
0:24:47 > 0:24:49A bat?
0:24:51 > 0:24:55No. You were so right until the last part.
0:24:55 > 0:24:56They're not blind.
0:24:56 > 0:24:59- An anteater?- Not an anteater, no.
0:24:59 > 0:25:02- A mole?- It's insectivorous so it could eat ants.
0:25:02 > 0:25:03Is it a mole?
0:25:03 > 0:25:06- Mole is the right answer. - I said mole!
0:25:06 > 0:25:08- Did you? Sorry!- I just said mole!
0:25:08 > 0:25:10- Did he say mole, ladies and gentlemen?- Yes!
0:25:10 > 0:25:14No, because sound is just a thing and it didn't travel!
0:25:16 > 0:25:20Yeah, if you didn't hear me say mole, then I didn't say mole!
0:25:20 > 0:25:24- So you need the points, I suspect, Alan.- I probably do.
0:25:24 > 0:25:28There are about 1,100 different species of bat, and none of them is sightless. Not one.
0:25:28 > 0:25:33- Is the mole completely sightless? - It can just distinguish between light and dark.
0:25:33 > 0:25:37- But essentially it's blind.- It can tell if the telly's on or off! - Yes, if you like!
0:25:37 > 0:25:40It can't tell if it's on standby!
0:25:40 > 0:25:44- How many moles are there in Ireland? - None.- Right.
0:25:44 > 0:25:47- There are none.- Why?- They're very pally with the snakes.
0:25:47 > 0:25:51Glaciation and the separation of Ireland, they never got back.
0:25:51 > 0:25:55- It was an island.- They could tunnel! - Like snakes.- Tunnel!
0:25:55 > 0:25:59- If any animal can tunnel, it's a mole.- Oh, sweet!- You say sweet,
0:25:59 > 0:26:04but almost certainly all photos of moles that are taken are of dead moles.
0:26:04 > 0:26:08- Because they fluff them up. - That's terrible!
0:26:08 > 0:26:12- Their eyes are always black slits. - It's like those greeting cards.
0:26:12 > 0:26:15A cat on a deckchair, or a cat and a mouse.
0:26:15 > 0:26:17They're all dead.
0:26:17 > 0:26:20I fear so. Yes, moles are as blind as the proverbial bat.
0:26:20 > 0:26:24Bats, perversely, aren't. Finally, the ultimate hypothetical question.
0:26:24 > 0:26:27Which came first, the chicken or the egg?
0:26:29 > 0:26:31Uh...
0:26:31 > 0:26:32- Chicken.- No!
0:26:34 > 0:26:37- The egg.- Egg is the right answer, yes.
0:26:37 > 0:26:41There's that old joke about the chicken and egg have just made love.
0:26:41 > 0:26:43They're having a post-coital cigarette.
0:26:43 > 0:26:47Chicken says to the egg, well, that answers that old question!
0:26:53 > 0:26:58As the scientist JBS Haldane said, anyone who can ask that question hasn't understood evolution.
0:26:58 > 0:27:02A chicken evolved from reptiles that laid eggs themselves.
0:27:02 > 0:27:06So the eggs were coming well before there was a chicken.
0:27:06 > 0:27:10So it did, indeed, come first, the egg.
0:27:10 > 0:27:14What's the longest recorded flight by a chicken, in time terms, not distance.
0:27:14 > 0:27:1613 seconds? Something like that?
0:27:16 > 0:27:18Yes.
0:27:19 > 0:27:22- Yes, it is 13 seconds!- Is it really?
0:27:22 > 0:27:25LAUGHTER AND APPLAUSE
0:27:29 > 0:27:36I don't claim that's true, but that is one of the oldest internet pieces of trivia I know,
0:27:36 > 0:27:40apart from a duck's quack does not echo and no-one knows why!
0:27:40 > 0:27:43- We know that isn't true.- No.
0:27:43 > 0:27:47So, anyway, birds evolved from egg-laying reptiles
0:27:47 > 0:27:50so there were definitely eggs before there were chickens.
0:27:50 > 0:27:56We emerge older but no wiser at the end of the only quiz to offer no answers, just more questions!
0:27:56 > 0:28:01But had there been answers, let's see who would hypothetically have won.
0:28:01 > 0:28:06Our theoretical winner tonight with two points is Sandi Toksvig!
0:28:10 > 0:28:15Notionally in second place is elf-master general, John Lloyd, with minus one!
0:28:18 > 0:28:24On paper in third place with a creditable minus seven, Johnny Vegas!
0:28:27 > 0:28:30Finally, proving that it's all academic and a dream,
0:28:30 > 0:28:33with minus 27, Alan Davies!
0:28:38 > 0:28:43So, that's all from this hypothetical edition of QI.
0:28:43 > 0:28:45Or is it? Yes, it is.
0:28:45 > 0:28:49So it's good night from Sandi, Johnny, John, Alan and me - good night!
0:29:11 > 0:29:14Subtitles by Red Bee Media Ltd